Isoquercitrin Loaded PEGylated Long Circulating Liposomes Improve Bone Mass and Reduce Oxidative Stress After Osteoporosis.

Osteoporosis has increasingly become a major public health concern because of its associated heightened risk of bone fragility and fractures. In order to avoid the adverse risk of hormone therapy, scientists have considered isoquercitrin (IQ) as a natural phytoestrogen to potentially prevent osteoporosis. However, IQ has poor solubility and bioavailability which culminates in rapid elimination of phytoestrogen. Herein, this study sought to solve limited applications of IQ by preparing IQ-loaded PEGylated long circulating liposomes (IQ-Lips) via thin-film hydration method. After appropriate characterization using zeta-potential, polydispersed index (PDI), particle size and entrapment efficiency (EE), IQ-Lips were applied to ovariectomized rat models to evaluate their effect on osteoporosis. The results showed that the prepared IQ-Lips exhibited smaller sized nanoparticles (125.35 ± 4.50 nm), excellent PDI (0.244 ± 0.001) and zeta-potential (-28.64 ± 0.71 mV) with stable property and higher EE (92.10 ± 0.32%). Importantly, administration of IQ-Lips through oral route increased aqueous solvability, bioavailability and circulation time of IQ. Moreover, the IQ-Lips could increase bone microstructural densities and bone mass, as well as reduce oxidative stress in ovariectomized rat models. Altogether, the IQ-Lips may serve as a novel avenue to potentially prolong the circulation of IQ in the body and improve the bioavailability of IQ for treatment of osteoporosis.